Chapter 3 Definitions Flashcards
A temperature measured in Kelvins or Rankines
Absolute Temperature
A fuel or oxidizer, often an ignitible liquid intentionally used to initiate a fire or increase the rate of growth or fire spread.
Accelerant
Someone’s or something’s surroundings, especially as they pertain to the local environment; for example, ambient air and ambient temperature.
Ambient
The maximum current, in amperes, that a conductor can carry continuously under the conditions of use without exceedings its temperature rating.
Ampacity
The unit of electric current that is equivalent to a flow of one coulomb per second; one coulomb is defined as 6.24 x 10 (18) electrons
Ampere
A high temperature luminous electric discharge across a gap or through a medium such as charred insulation.
Arc
The systematic evaluation of the electrical circuit configuration, spatial relationship of the circuit components, and identification of electrical arc sites to assist in the identification of the area of origin and analysis of the fire’s spread.
Arc Mapping
The location on a conductor with localized damage that resulted from an electrical arc.
Arc Site
Arcing associated with a matrix of charred material (e.g., charred conductor insulation) that acts as a semiconductive medium.
Arcing through char.
A structure, part of a structure, or general geographic location within a fire scene, in which the “point of origin”” of a fire or explosion is reasonably believed to be located.
Area of Origin
A fire pattern displayed on the cross section of burned wooden structural member
Arrow pattern
The crime of maliciously and intentionally, or recklessly, starting a fire or causing an explosion.
Arson
Initiation of combustion by heat but without a spark or flame
Autoignition
The lowest temperature at which a combustible material ignites in air without a spark or flame.
Autoignition temperature.
A deflagration resulting from the sudden introduction of air into a confined space containing oxygen deficient products of incomplete combustion.
Backdraft.
A rounded globule of re-solidified metal at the end of the remains of an electrical conductor that was caused by arcing and is characterized by a sharp line of demarcation between the melted and unmelted conductor surfaces.
Bead
The expanding leading edge of an explosion reaction that separates a major difference in pressure between normal ambient pressure ahead of the front and potentially damaging high pressure at and behind the front.
Blast Pressure Front
Boiling liquid expanding vapor explosion
BLEVE
The permanent joining of metallic parts to form an electrically conductive path that ensures electrical continuity and capacity to conduct safely any current likely to be imposed.
Bonding
The quantity of heat required to raise the temperature of one pound of water 1 degree F at the pressure of 1 atmosphere and temperature of 60 F
British Thermal Unit (Btu)
A fire effect realized in gypsum products, including wallboard, as a result of exposure to heat that drives off free and chemically bound water.
Calcination of Gypsum
The circumstances, conditions, or agencies that brought about or resulted in the fire or explosion incident, damage to property resulting from the fire or explosion incident, or bodily injury or loss of life resulting from the fire or explosion incident.
Cause
A relatively thin layer of flowing hot gases that develops under a horizontal surface as a result of plume impingement and flowing gas being forced to move horizontally.
Ceiling Jet
A buoyant layer of hot gases and smoke produced by a fire in a compartment.
Ceiling Layer
Carbonaceous material that has been burned or pyrolyzed and has a blackened appearance.
Char
Convex segments of carbonized material separated by cracks or crevasses that form on the surface of char, forming on material such as wood as a result of pyrolysis or burning.
Char Blisters
A distinct and visible fire effect generally apparent on noncombustible surfaces after combustible layers (such as soot, paint, and paper) have been burned away. The effect may also appear where soot has failed to be deposit
Clean Burn
An instrument that samples air and indicates whether there are ignitable vapors or gases present.
Combustible gas Indicator.
Any liquid that has a closed-cup flash point at or above 37.8 Decrees Celsius. (100.00F)
Combustible Liquid
A chemical process of oxidation that occurs at a rate fast enough to produce heat and usually light in the form of either a glow or flame.
Combustion.
An ignition source that has sufficient energy and is capable of transferring that energy to the fuel long enough to raise the fuel to its ignition temperature.
Competent Ignition source.
Heat transfer to another body or within a body by direct contact.
Conduction
Heat transfer by circulation within a medium such as a gas or a liquid.
Convection
The tendency of a material to move or deform permanently to relieve stresses.
Creep
A flow of electric charge.
Current
The process by which conclusions are drawn by logical inference from given premises.
Deductive reasoning
Propagation of a combustion zone at a velocity that is less than the speed of sound in the unreacted medium
deflagration
A gas, vapor, dust, particulate, aerosol, mist, fog, or hybrid mixture of these, suspended in the atmosphere, which is capable of being ignited and propagating a flame front.
Diffuse fuel
A flame in which fuel and air mix or diffuse together at the region of combustion
Diffusion flame.
The spread of fire by the dropping or falling of burning materials. Synonymous with “fall down”.
Drop down.
Temperatures reached in fires that produce physical effects that can be related to specific temperature ranges
Effective fire termperatures
Factual data that is based on actual measurement, observation or direct sensory experience rather than on theory.
Empirical data
The process of air or gases being drawn into a fire, plume, or jet.
Entrainment.
A logical, systemic examination of an item, component, assembly or structure and its place and function within a system, conducted in order to identify and analyze the probability, causes, and consequences of potential and real failures
Failure analysis
The time in minutes, determined under specific laboratory conditions, at which the stud or joist in contact with the exposed protective membrane in a protected combustible assembly reaches an average temperature rise of 121 C (250) or an individual temperature rise of 163 C as measured behind the protective membrane nearest the fire on the plane of the wood.
Finish rating
The process of determining the origin, cause, development, responsibility and when required a failure analysis of a fire or explosion.
Fire analysis
The circumstances, conditions or agencies that bring together a fuel, ignition source, and oxidizer resulting in a fire or a combustion explosion.
Fire cause
The detailed study of how chemistry, fire science, and the engineering disciplines of fluid mechanics and heat transfer interact to influence fire behavior.
Fire Dynamics
The process of determining the origin, cause, and development of a fire or explosion.
Fire investigation
The visible or measurable physical changes, or identifiable shapes, formed by a fire effect or group of fire effects.
Fire patterns
The process of recreating the physical scene during fire scene analysis investigation or through the removal of debris and the placement of contents or structural elements in their pre-fire positions.
Fire scene reconstruction.
The first fuel ignited is that which first sustains combustion beyond the ignition source.
First Fuel ignited
The flaming leading edge of a propagation combustion reaction zone.
Flame Front
The condition where unburned fuel (pyrolysate) from the originating fire has accumulated in the ceiling layer to a sufficient concentration that it ignites and burns; can occur without ignition of, or prior to, the ignition of other fuels separate from the origin.
Flameover
The upper or lower concentration limit at a specified temperature and pressure of a flammable gas or a vapor of an ignitable liquid and air, expressed as a percentage of fuel by volume that can be ignited.
Flammable limit
A fire that spreads by means of a flame front rapidly through a diffuse fuel, such as dust, gas, or the vapors of an ignitable liquid, without the production of damaging pressure.
Flash fire
The lowest temperature of a liquid, as determined by specific laboratory tests, at which the liquid gives off vapors at a sufficient rate to support a momentary flame across its surface.
Flash point of a liquid
A transition phase in the development of a compartment fire in which surfaces exposed to thermal radiation reach ignition temperature more or less simultaneously and fire spreads rapidly throughout the space, resulting in full room involvement or total involvement of the compartment or enclosed space.
Flashover
The application of science to answer questions of interest to the legal system.
Forensic Science
Natural gas, manufactured gas, LP-Gas, and similar gases commonly used for commercial or residential purposes such as heating, cooling, or cooking.
Fuel Gas
The total quantity of combustible contents of a building, space, or fire are, including interior finish and trim, expressed in heat units or the equivalent weight in wood.
Fuel Load
A fire in which the heat release rate and growth rate are controlled by the characteristics of the fuel, such as quantity and geometry, and in which adequate air for combustion is available.
Fuel-Controlled Fire.
Condition in a compartment fire in which the entire volume is involved in combustion of varying intensities
Full room involvement.
Luminous burning of solid material without a visible flame.
Glowing Combustion
A conducting connection, whether intentional or accidental, between an electrical circuit or equipment and earth or to some conducting body that serves in place of the earth.
Ground
An unintended current that flows outside the normal circuit path, such as (a) through the equipment grounding conductor; (b) through conductive material in contact with lower potential (such as earth), other than the electrical system ground (metal water or plumbing pipes, etc.) or (c) through a combination of these ground return paths.
Ground fault
A form of energy characterized by vibration of molecules and capable of initiating and supporting chemical changes and change of state.
Heat
An arrow used in a fire scene drawing to show the direction of heat, smoke, or flame flow.
Heat and flame vector
The measure of the rate of heat transfer to a surface, expressed in kilowatts/m2 or Btu/ft2 . sec
Heat flux
The heat energy that brings about ignition
Heat of ignition
The rate at which heat energy is generated by burning.
HRR Heat release rate
A rapid pressure rise or high force explosion characterized by a shattering effect on the confining structure or container and long missile distance.
High-order damage
Any substance that will spontaneously ignite or explode upon exposure to an oxidizer.
Hypergolic material
The process of initiating self-sustained combustion.
Ignition
The quantity of heat energy that should be absorbed by a substance to ignite and burn.
Ignition Energy
Minimum temperature a substance should attain in order to ignite under specific test conditions
Ignition temperature
The time between the application of an ignition source to a material and the onset of self-sustained combustion.
Ignition Time
A fire that is deliberately set with the intent to cause the fire to occur in an area where the fire should not be.
Incendiary fire
The process by which a person starts from a particular experience and proceeds to generalizations. The process by which hypotheses are developed based upon observable or known facts and the training, experience, knowledge, and expertise of the observer.
Inductive reasoning
Any person, entity, or organization, including their representatives, with statutory obligations or whose legal rights or interests may be affected by the investigation of a specific incident.
Interested party
A line on a diagram connecting points of equal char depth
Isochar
The preferred SI unit of heat, energy, or work.
Joule
How many joules are in a calorie?
4.184
There are ____ jouiles in a BTU.
1055
A _____ is the heat produced when one ampere is passed through a resistance of one ohm for one second.
Joule
The systematic process of removing debris from the top down and observing the relative location of artifacts at the fire scene.
Layering
An explosive that has a reaction velocity of less that 1000m/sec
Low explosive
A slow rate of pressure rise or low-force explosion characterized by a pushing or dislodging effect on the confining structure or container and by short missile distances.
Low-order damage.
The fuel that is first set on fire by the heat of ignition; to be meaningful, both a type of material and a form of material should be identified.
Material first ignited
A material that, in the form in which it is used and under the condition anticipated, will not ignite, burn, support combustion, or release flammable vapors when subjected to fire or heat.
noncombustible material.
Not readily capable of burning with a flame. (2) Not liable to ignite and burn when exposed to flame.
Nonflammable
The SI unit of electrical impedance or, in the direct current case, electrical resistance
Ohm
The general location where a fire or explosion began
Origin
Any current in excess of the rated current of equipment or the ampacity of a conductor; it may result from an overload, short circuit, or ground fault.
Overcurrent
A fire fighting term involving the process of final extinguishment after the min body of the fire has been knocked down. All traces of fire must be extinguished at this time.
Overhaul
The column of hot gases, flames and smoke rising above a fire; also called convection column, thermal updraft, or thermal column.
Plume
The exact physical location within the area of origin where a heat source and the fuel interact, resulting in a fire or explosion.
Point of Origin
A flame for which the fuel and oxidizer are mixed prior to combustion, as in a laboratory Bunsen burner or a gas cooking range
Premixed flame
Application or use of measure to prevent damage, change or alteration, or deterioration.
Preservation
The cause that directly produces the effect without the intervention of any other cause.
Proximate cause
Product of decomposition through heat; a product of a chemical change caused by heating.
Pyrolysate
A process in which material is decomposed, or broken down, into simpler molecular compound by the effects of heat alone; pyrolysis often precedes combustion.
Pyrolysis
Any substance that spontaneously ignites upon exposure to atmospheric oxygen
Pyrophoric material
Heat energy carried by electromagnetic waves that are longer than light waves and shorter than radio waves; radiant heat (electromagnetic radiation) increases the sensible temperature of any substance capable of absorbing the radiation, especially solid and opaque objects.
Radiant heat
The systematic pursuit of knowledge involving the recognition and definition of a problem; the collection of data through observation and experimentation;
Scientific method
A craterlike indentation created at the point of origin of some explosions.
Seat of explosion
An explosions with a highly localized point of origin, such as a crater.
seated explosion
The result of exothermic reactions, occurring spontaneously in some materials under certain conditions, whereby heat is generated at a rate sufficient to raise the temperature of the material.
Self heating
Ignition resulting from self-heating, synonymous with spontaneous ignition
self-ignition
The minimum temperature at which the self-heating properties of a material lead to ignition.
Self-ignition temperature
An abnormal connection of low resistance between normal circuit conductors where the resistance is normally much greater; this is an overcurrent situation but is not an overload.
Short Circuit
The airborne solid and liquid particulates and gases evolved when a material undergoes pyrolysis or combustion, together with the quantity of air that is entrained or otherwise mixed into the mass.
Smoke
The condensed residue of suspended vapors and liquid products of incomplete combustion.
Smoke condensate
Combustion without flame, usually with incandescence and smoke.
smoldering
Black particles of carbon produced in a flame.
Soot
Chipping or pitting of concrete or masonry surfaces.
spalling
Loss, destruction, or material altercation of an object or document that is evidence or potential evidence in a legal proceeding by one who has the responsibility for its preservation.
Spoliation
Process whereby a material increases in temperature without drawing heat from its surroundings.
Spontaneous Heating
A fuel that is subject to ignition by thermal radiation such as from a flame or a hot gas layer.
Target fuel
The increase in length, volume, or surface area of a body with rise in temperature.
Thermal expansion.
The study of the science, methodology, and practice of temperature measurement.
Thermometry
Solid or liquid fuel used to intentionally spread or accelerate the spread of a fire from one area to another.
Trailer
The has phase of a substance, particularly of those that are normally liquids or solids at ordinary temperatures.
Vapor
An opening for the passage of, or dissipation of, fluids, such as gases, fumes, smoke, and the like.
Vent
A fire in which the heat release rate or growth is controlled by the amount of air available to the fire.
Ventilation controlled fire.
The unit of electrical pressure (electromotive force) represented by the symbol “E”; the difference in potential required to make a current of one ampere flow through a resistance of one ohm.
Volt
Unit of power, or rate of work, equal to one joule per second, or the rate of work represented by a current of one ampere under the potential of one volt.
Watt
